Gallium nitride driving circuit and switching power supply

Abstract

The utility model discloses a gallium nitride driving circuit and a switching power supply. The gallium nitride driving circuit comprises a resistor R1, a capacitor C1, a voltage-regulator tube D1, a voltage-regulator tube D2, a driving signal input port Vgate, a driving signal output port Vgs and a grounding port GND. The driving signal input port Vgate is simultaneously connected with one end of the resistor R1 and one end of the capacitor C1, the other end of the resistor R1, the other end of the capacitor C1 and the cathode of the voltage-regulator tube D1 are simultaneously connected with the driving signal output port Vgs, the anode of the voltage-regulator tube D1 is connected with the anode of the voltage-regulator tube D2, and the cathode of the voltage-regulator tube D2 is connected with the grounding port GND; wherein the gallium nitride driving circuit further comprises a voltage limiting clamping circuit which is connected between the driving signal output port Vgs and the grounding port GND, and the voltage limiting clamping circuit is used for limiting a driving output signal of the driving signal output port Vgs within the withstand voltage of a gate electrode and a source electrode of the gallium nitride power tube. The reliability of the switching power supply can be improved.

Description

Technical Field

[0001] The utility model relates to a driving circuit, in particular to a gallium nitride driving circuit and a switching power supply. Background Art

[0002] Gallium nitride power tubes have been widely used in various fields because of their extremely small on-resistance and good switching characteristics, especially in the field of switching power supplies. Switching power supplies using gallium nitride power tubes can achieve higher efficiency and the problem of high heat generation is also greatly improved.

[0003] In addition to the above advantages, GaN power tubes also have their own unique limitations. Due to process problems, the gate-source voltage of GaN power tubes cannot be made too high, and their conduction threshold is very small. If they are not designed well, they are very easy to be mis-conducted. Therefore, the driving circuit of GaN power tubes cannot directly share the driving circuit of ordinary silicon MOS tubes. It is necessary to optimize and improve the driving circuit of ordinary silicon MOS tubes before using them to drive GaN power tubes, or use special GaN driver chips to drive GaN power tubes.

[0004] Considering the compatibility with ordinary silicon MOS tubes and the limited selection of specialized gallium nitride driver chips on the market, the current common solution is to improve the driving circuit of ordinary silicon MOS tubes and use it to drive gallium nitride power tubes. Figure 1 This is a schematic diagram of the existing gallium nitride driving circuit on the market: it includes a resistor R1, a capacitor C1, a zener diode D1, a zener diode D2, a driving signal input port Vgate, a driving signal output port Vgs and a ground port GND; the driving signal input port Vgate is connected to one end of the resistor R1 and one end of the capacitor C1, the other end of the resistor R1 is connected to the other end of the capacitor C1, and then connected to the cathode of the zener diode D1 and the driving signal output port Vgs, the anode of the zener diode D1 is connected to the anode of the zener diode D2, and the cathode of the zener diode D2 is connected to the ground port GND.

[0005] The inventor of this application used the switching power supply product development process Figure 1 When testing the circuit, it was found that the GaN power tube was easily damaged. After in-depth research, it was found that the reason was that the gate-source voltage of the GaN power tube was easily exceeded. The specific analysis is as follows:

[0006] Assume that the voltage regulation value of the voltage regulator D1 is VZD1, and the forward conduction voltage is VD1. The voltage regulation value of the voltage regulator D2 is VZD2, and the forward conduction voltage is VD2. The forward conduction voltages of VD1 and VD2 are about 0.7V.

[0007] When the driving input signal Vgate is at a high level: due to the high voltage value of the driving input signal Vgate, the voltage regulator D1 is broken down and works in a voltage-stabilized state. The voltage regulator D2 is forward-conducted. At this time, the Vgs voltage is VZD1+VD2, and the remaining voltage Vgate-(VZD1+VD2) falls on the capacitor C1. In this way, the voltage limit clamping of the driving signal is realized, and the driving output signal Vgs is limited to VZD1+VD2. By simply selecting the voltage value of the voltage regulator D1, the driving threshold of the GaN power tube can be matched, and the GaN power tube can be driven normally while being within the safe withstand voltage of its drive.

[0008] When the driving input signal Vgate is low level: the capacitor C1 is charged to Vgate-(VZD1+VD2) in the previous stage, and the driving input signal Vgate becomes low level 0V at this time, and the two ends of the capacitor C1 will not change suddenly, so the Vgs voltage becomes negative. The voltage regulator D2 is broken down and works in the voltage regulation state. The voltage regulator D1 is forward-conducted. The driving output signal Vgs is limited to -(VD1+VZD2).

[0009] The conduction threshold of conventional GaN is about 1V. The gate-source withstand voltage is very low, about -3V~+5V. When the driving input signal Vgate is high, the above-mentioned market solution needs to satisfy (VZD1+VD2)<5V, so the voltage value of the Zener D1 is usually selected to be 3.3V. When the driving input signal Vgate is low, it needs to satisfy (VD1+VZD2)<3V, so the voltage value of the Zener D2 is extremely difficult to choose. Even if a 2.4V Zener is selected, it is very easy to exceed the 3V withstand voltage after adding the forward conduction voltage VD1 of the Zener D1, causing the GaN power tube to be easily damaged due to the gate-source withstand voltage exceeding the specification.

[0010] It should be noted that the above information disclosed in the background technology section is only intended to deepen the understanding of the overall background technology of this application, and should not be regarded as admitting or suggesting in any form that the information constitutes prior art already known to those skilled in the art. Utility Model Content

[0011] In view of this, the utility model proposes a gallium nitride driving circuit and a switching power supply, which can limit the voltage of the driving input signal, so that no matter whether the driving input signal Vgate is at a high level or a low level, the driving output signal Vgs is within the gate-source withstand voltage of the gallium nitride power tube, thereby improving the overall reliability of the product.

[0012] As a first aspect of the present invention, the technical solution of the embodiment of the gallium nitride driving circuit provided is as follows:

[0013] A gallium nitride driving circuit is used to drive a gallium nitride power tube, the gallium nitride driving circuit comprising: a resistor R1, a capacitor C1, a voltage regulator D1, a voltage regulator D2, a driving signal input port Vgate, a driving signal output port Vgs and a ground port GND; the driving signal input port Vgate is simultaneously connected to one end of the resistor R1 and one end of the capacitor C1, the other end of the resistor R1, the other end of the capacitor C1 and the cathode of the voltage regulator D1 are simultaneously connected to the driving signal output port Vgs, the anode of the voltage regulator D1 is connected to the anode of the voltage regulator D2, and the cathode of the voltage regulator D2 is connected to the ground port GND; wherein: the gallium nitride driving circuit also includes a voltage limiting clamping circuit connected between the driving signal output port Vgs and the ground port GND, and the voltage limiting clamping circuit is used to limit the driving output signal of the driving signal output port Vgs to within the gate-source withstand voltage of the gallium nitride power tube.

[0014] Preferably, the voltage limiting clamp circuit comprises a PMOS tube TR2, a gate and a source of the PMOS tube TR2 are simultaneously connected to the drive signal output port Vgs, and a drain of the PMOS tube TR2 is connected to the ground port GND.

[0015] Furthermore, the gallium nitride driving circuit also includes an isolation circuit, one end of which is connected to the other end of the resistor R1, the other end of the capacitor C1, the cathode of the voltage regulator tube D1 and the connection point of the gate of the PMOS tube TR2, and the other end of the isolation circuit is connected to the connection point of the source of the PMOS tube TR2 and the driving signal output port Vgs, and the isolation circuit is used to block the capacitor C1 from participating in the high-frequency resonance of the gallium nitride power tube.

[0016] Preferably, the isolation circuit comprises a diode D3, an anode of the diode D3 is one end of the isolation circuit, and a cathode of the diode D3 is the other end of the isolation circuit.

[0017] Furthermore, the gallium nitride driving circuit also includes an amplifier circuit, one end of which is connected to the other end of the resistor R1, the other end of the capacitor C1, the cathode of the voltage regulator D1 and the connection point of the gate of the PMOS tube TR2, and the other end of the amplifier circuit is connected to the connection point of the source of the PMOS tube TR2 and the driving signal output port Vgs. The amplifier circuit is used to amplify the driving output signal of the driving signal output port Vgs and then output it, thereby increasing the driving capability of the gallium nitride driving circuit.

[0018] Preferably, the amplifier circuit comprises a transistor Q1, the base of the transistor Q1 is one end of the amplifier circuit, the emitter of the transistor Q1 is the other end of the amplifier circuit, and the collector of the transistor Q1 is used for inputting a power supply voltage Vcc.

[0019] Furthermore, the gallium nitride driving circuit further includes a resistor R2, one end of the resistor R2 is connected to the driving signal input port Vgate, and the other end of the resistor R2 is connected to a connection point between one end of the resistor R1 and one end of the capacitor C1.

[0020] Furthermore, the gallium nitride driving circuit further includes a diode D4, a cathode of the diode D4 is connected to the driving signal input port Vgate, and an anode of the diode D4 is connected to a connection point between one end of the resistor R1 and one end of the capacitor C1.

[0021] Furthermore, the gallium nitride driving circuit also includes a resistor R2 and a diode D4; one end of the resistor R2 is connected to the driving signal input port Vgate, and the other end of the resistor R2 is connected to a connection point between one end of the resistor R1 and one end of the capacitor C1; the cathode of the diode D4 is connected to the driving signal input port Vgate, and the anode of the diode D4 is connected to a connection point between one end of the resistor R1 and one end of the capacitor C1.

[0022] As a second aspect of the present invention, the technical solution of the embodiment of the switching power supply provided is as follows:

[0023] A switching power supply includes a gallium nitride power tube, wherein the switching power supply also includes the gallium nitride driving circuit described in any one of the first aspects above, and the driving signal output port Vgs is connected to the gate of the gallium nitride power tube.

[0024] Compared with the prior art, the utility model has the following beneficial effects:

[0025] The gallium nitride driving circuit in the embodiment of the utility model includes a voltage limiting clamping circuit, which can limit the voltage of the driving input signal, so that no matter whether the driving input signal is at a high level or a low level, the driving output signal can be clamped within the gate-source withstand voltage of the gallium nitride power tube, thereby preventing the gallium nitride power tube from being easily damaged due to the gate-source withstand voltage exceeding the specification, thereby improving the overall reliability of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the schematic diagram of the existing gallium nitride driving circuit on the market;

[0027] Figure 2 This is a schematic diagram of a first gallium nitride driving circuit according to a first embodiment of the utility model;

[0028] Figure 3 This is a schematic diagram of a second gallium nitride driving circuit of the first embodiment of the utility model;

[0029] Figure 4This is a schematic diagram of a third gallium nitride driving circuit of the first embodiment of the utility model;

[0030] Figure 5 This is a circuit schematic diagram of a switching power supply according to the second embodiment of the utility model. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this application.

[0032] It should be noted that the terms "including" and "having" and any variations thereof described in the specification and claims of the present application are intended to cover non-exclusive inclusions. For example, the inclusion of a series of components, unit circuits or control timings is not necessarily limited to those components, unit circuits or control timings clearly listed, but may include components, unit circuits or control timings that are not clearly listed or inherent to these circuits.

[0033] In addition, the embodiments and features of the embodiments in this application may be combined with each other if there is no conflict.

[0034] It should be understood that, in the specification and the claims, when an element is described as being “connected” to another element, the element may be “directly connected” to the other element, or be “connected” to the other element through a third element; when a step is described as being continued to another step, the step may be directly continued to the other step, or be continued to the other step through a third step.

[0035] First embodiment

[0036] This embodiment provides a gallium nitride driving circuit for driving a gallium nitride power tube. Figure 2 This is a schematic diagram of a first gallium nitride driving circuit according to the first embodiment of the utility model. Figure 3 The second gallium nitride driving circuit schematic diagram of the first embodiment of the utility model is shown in FIG. Figure 4 This is a schematic diagram of the third gallium nitride driving circuit of the first embodiment of the utility model, see Figures 2 to 4, wherein the gallium nitride driving circuit includes: a resistor R1, a capacitor C1, a voltage regulator D1, a voltage regulator D2, a driving signal input port Vgate, a driving signal output port Vgs and a ground port GND; the driving signal input port Vgate is simultaneously connected to one end of the resistor R1 and one end of the capacitor C1, the other end of the resistor R1, the other end of the capacitor C1 and the cathode of the voltage regulator D1 are simultaneously connected to the driving signal output port Vgs, the anode of the voltage regulator D1 is connected to the anode of the voltage regulator D2, and the cathode of the voltage regulator D2 is connected to the ground port GND; wherein: the gallium nitride driving circuit also includes a voltage limiting clamping circuit, which is connected between the driving signal output port Vgs and the ground port GND, and the voltage limiting clamping circuit is used to limit the driving output signal of the driving signal output port Vgs to within the gate-source withstand voltage of the gallium nitride power tube.

[0037] The gallium nitride driving circuit in the embodiment of the utility model includes a voltage limiting clamping circuit, which can limit the voltage of the driving input signal, so that no matter whether the driving input signal is at a high level or a low level, the driving output signal can be clamped within the gate-source withstand voltage of the gallium nitride power tube, thereby preventing the gallium nitride power tube from being easily damaged due to the gate-source withstand voltage exceeding the specification, thereby improving the overall reliability of the product.

[0038] Please continue to see Figures 2 to 4 The voltage limiting clamping circuit includes a PMOS tube TR2, a gate and a source of the PMOS tube TR2 are simultaneously connected to the drive signal output port Vgs, and a drain of the PMOS tube TR2 is connected to the ground port GND.

[0039] Please continue to see Figure 2 and Figure 4 The gallium nitride driving circuit also includes an isolation circuit, one end of the isolation circuit is connected to the other end of the resistor R1, the other end of the capacitor C1, the cathode of the voltage regulator tube D1 and the connection point of the gate of the PMOS tube TR2, and the other end of the isolation circuit is connected to the connection point of the source of the PMOS tube TR2 and the driving signal output port Vgs. The isolation circuit is used to block the capacitor C1 from participating in the high-frequency resonance of the gallium nitride power tube.

[0040] After solving the problem of the gallium nitride power tube being easily damaged in the background technology, the inventors of the present application discovered that the switching power supply is prone to abnormal operation and damage. After research, it was found that the reason is: at the moment when the gallium nitride power tube is switched on, the capacitor C1 is easily involved in the high-frequency resonance of the gallium nitride power tube, resulting in the presence of a high-frequency resonance component in the drive signal output from the drive signal output port Vgs. Because the conduction threshold of conventional gallium nitride is approximately 1V, the presence of a high-frequency resonance component in the drive signal output from the drive signal output port Vgs can easily mis-trigger the gallium nitride power tube, causing the gallium nitride power tube to be mis-turned on, resulting in abnormal operation of the switching power supply and damage. Therefore, Figure 2 and Figure 4The gallium nitride drive circuit also includes an isolation circuit, which blocks the capacitor C1 so that it does not participate in the high-frequency resonance of the gallium nitride power tube, making it difficult for the gallium nitride power tube to be misconnected, thereby improving the overall reliability of the product.

[0041] Please continue to see Figure 2 and Figure 4 , wherein the isolation circuit includes a diode D3, wherein the anode of the diode D3 is one end of the isolation circuit, and the cathode of the diode D3 is the other end of the isolation circuit.

[0042] Please continue to see Figure 3 The gallium nitride driving circuit also includes an amplifier circuit, one end of which is connected to the other end of the resistor R1, the other end of the capacitor C1, the cathode of the voltage regulator D1 and the connection point of the gate of the PMOS tube TR2, and the other end of the amplifier circuit is connected to the connection point of the source of the PMOS tube TR2 and the driving signal output port Vgs. The amplifier circuit is used to amplify the driving output signal of the driving signal output port Vgs and then output it, thereby increasing the driving capability of the gallium nitride driving circuit.

[0043] Please continue to see Figure 3 The amplifier circuit includes a transistor Q1, a base of the transistor Q1 is one end of the amplifier circuit, an emitter of the transistor Q1 is the other end of the amplifier circuit, and a collector of the transistor Q1 is used for inputting a power supply voltage Vcc.

[0044] Figure 2 The working principle of the circuit is analyzed as follows:

[0045] ①When the driving input signal Vgate is high:

[0046] Because the voltage value of the driving input signal Vgate is high, the voltage regulator D1 is broken down and works in the voltage regulation state; the voltage regulator D2 is forward-conducted; and the diode D3 is in the on state. The driving input signal Vgate is provided to the driving output signal Vgs through the capacitor C1 and the diode D3. At this time, the Vgs voltage is (VZD1+VD2)-VD3, and the voltage Vgate-(VZD1+VD2) falls on the capacitor C1; the voltage across the gate source of the PMOS tube TR2 is equal to the conduction voltage drop of the diode D3, and the PMOS tube TR2 is in the off state.

[0047] ②When the driving input signal Vgate is low:

[0048] In the previous stage, capacitor C1 is charged to Vgate-(VZD1+VD2). At this time, the driving input signal Vgate becomes a low level 0V, and there is no sudden change at both ends of capacitor C1. The gate voltage of the PMOS tube is quickly pulled down to a negative voltage.

[0049] At this time, the voltage regulator D2 is broken down and works in the voltage regulation state. The voltage regulator D1 is forward-conducting. The gate voltage of the PMOS tube is clamped to -(VD1+VZD2), the gate voltage is less than the source voltage, and the PMOS tube is quickly turned on. Vgs is pulled down by the PMOS tube, and the energy of Vgs is discharged to the ground through the source and drain of the PMOS tube. At this time, the voltage across Vgs is close to 0V.

[0050] The function of resistor R1 is to provide a discharge circuit for capacitor C1 when the product is turned off, which is equivalent to a reset function.

[0051] In summary, when the driving input signal Vgate is at a high level, the driving output signal Vgs is clamped to (VZD1+VD2)-VD3, where VD2 and VD3 are approximately equal to 0.7V. By simply setting the voltage value of the voltage regulator D1, the driving signal voltage value of GaN can be guaranteed to be within the withstand voltage specification.

[0052] When the driving input signal Vgate is at a low level, the driving output signal Vgs is pulled down to 0V by the PMOS tube, which is also within the withstand voltage specification.

[0053] At the same time, capacitor C1 is not directly connected to the GaN power tube, but is blocked by diode D3 and PMOS tube TR2, so it will not directly participate in the high-frequency resonance of the GaN power tube, and will not be mislead by the high-frequency resonance, thus improving the overall reliability of the product.

[0054] Figure 3 Circuit working principle and Figure 2 The circuit works in a similar way, except that Figure 3 When the driving input signal Vgate of the circuit is at a high level, the voltage regulator D1 is broken down and works in a voltage stabilization state; the voltage regulator D2 is forward-conducted. The anode voltage of the voltage regulator D1 does not directly provide driving capability to the driving output signal Vgs, but is added to the base of the transistor Q1, so that after the transistor Q1 is turned on, the power supply Vcc provides energy to the driving output signal Vgs, which can greatly increase the driving capability of the driving circuit 101.

[0055] Please continue to see Figure 4 , which is in Figure 2 On the basis of the above, a resistor R2 and a diode D4 are added; one end of the resistor R2 is connected to the drive signal input port Vgate, and the other end of the resistor R2 is connected to the connection point between one end of the resistor R1 and one end of the capacitor C1; the cathode of the diode D4 is connected to the drive signal input port Vgate, and the anode of the diode D4 is connected to the connection point between one end of the resistor R1 and one end of the capacitor C1.

[0056] Figure 4 Circuit working principle and Figure 2The circuit works in a similar way, but the difference is that the existence of resistor R2 makes the rising edge of the driving input signal Vgate pass through the delay drive of resistor R2, making the rising edge of the entire driving output signal Vgs smoother. The existence of diode D4 makes the energy of the falling edge of the driving input signal Vgate not pass through resistor R2, but directly pass through diode D4, making the falling edge of the entire driving output signal Vgs faster and accelerating the shutdown of the driving output signal Vgs.

[0057] Second embodiment

[0058] The present embodiment provides a switching power supply, the switching power supply includes a gallium nitride power tube, wherein the switching power supply further includes any gallium nitride drive circuit in the first embodiment, and the drive signal output port Vgs is connected to the gate of the gallium nitride power tube. Since the switching power supply in the present embodiment includes any gallium nitride drive circuit in the first embodiment, the reliability is improved.

[0059] Figure 5 This is a circuit schematic diagram of a switching power supply of the second embodiment of the utility model, wherein TR1 is a gallium nitride power tube connected between the opposite-name end of the primary winding of the transformer T1 and the ground terminal, the driving circuit 101 adopts any gallium nitride driving circuit in the first embodiment, and the signal of the driving signal input port Vgate of the driving circuit 101 is provided by the main control chip IC1.

[0060] It should be noted that Figure 5 The circuit is only an example of a switching power supply and should not limit the protection scope of the present invention. The topology type of the switching power supply and the source of the Vgate signal at the drive signal input port can be selected by technicians in this field as needed, and there is no restriction on how to design the present invention.

[0061] The above are only implementation modes of the present invention. It should be pointed out that the above implementation modes should not be regarded as limitations on the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. In addition, the gallium nitride driving circuit of the present invention is versatile. In addition to being applicable to switching power supplies, it can also be applied to other electronic devices including gallium nitride power tubes. The application scenario of the switching power supply should not be regarded as limiting the protection scope of the present invention.

Claims

1. A gallium nitride driving circuit for driving a gallium nitride power tube, the gallium nitride driving circuit comprising: Resistor R1, capacitor C1, voltage regulator D1, voltage regulator D2, drive signal input port Vgate, drive signal output port Vgs and ground port GND; The drive signal input port Vgate is simultaneously connected to one end of the resistor R1 and one end of the capacitor C1, the other end of the resistor R1, the other end of the capacitor C1, and the cathode of the voltage-stabilizing tube D1 are simultaneously connected to the drive signal output port Vgs, the anode of the voltage-stabilizing tube D1 is connected to the anode of the voltage-stabilizing tube D2, and the cathode of the voltage-stabilizing tube D2 is connected to the ground port GND; it is characterized in that: the gallium nitride drive circuit also includes a voltage limiting clamp circuit connected between the drive signal output port Vgs and the ground port GND, and the voltage limiting clamp circuit is used to limit the drive output signal of the drive signal output port Vgs to within the gate-source withstand voltage of the gallium nitride power tube.

2. The gallium nitride driving circuit according to claim 1, wherein: The voltage limiting clamp circuit includes a PMOS transistor TR2 , a gate and a source of the PMOS transistor TR2 are connected to the drive signal output port Vgs, and a drain of the PMOS transistor TR2 is connected to the ground port GND.

3. The gallium nitride driving circuit according to claim 2, wherein: The gallium nitride driving circuit further includes an isolation circuit, one end of which is connected to the other end of the resistor R1, the other end of the capacitor C1, the cathode of the voltage regulator D1, and the connection point of the gate of the PMOS transistor TR2, and the other end of the isolation circuit is connected to the connection point of the source of the PMOS transistor TR2 and the driving signal output port Vgs. The isolation circuit is used to prevent the capacitor C1 from participating in the high-frequency resonance of the gallium nitride power tube.

4. The gallium nitride driving circuit according to claim 3, wherein: The isolation circuit includes a diode D3 , wherein the anode of the diode D3 is one end of the isolation circuit, and the cathode of the diode D3 is the other end of the isolation circuit.

5. The gallium nitride driving circuit according to claim 2, wherein: The gallium nitride driving circuit also includes an amplifier circuit, one end of which is connected to the other end of the resistor R1, the other end of the capacitor C1, the cathode of the voltage regulator D1, and the connection point of the gate of the PMOS transistor TR2, and the other end of the amplifier circuit is connected to the connection point of the source of the PMOS transistor TR2 and the driving signal output port Vgs. The amplifier circuit is used to amplify the driving output signal of the driving signal output port Vgs and then output it, thereby increasing the driving capability of the gallium nitride driving circuit.

6. The gallium nitride driving circuit according to claim 5, characterized in that: The amplifier circuit includes a transistor Q1 , wherein the base of the transistor Q1 is one end of the amplifier circuit, the emitter of the transistor Q1 is the other end of the amplifier circuit, and the collector of the transistor Q1 is used for inputting a power supply voltage Vcc.

7. The gallium nitride driving circuit according to any one of claims 1 to 6, characterized in that: The gallium nitride driving circuit further includes a resistor R2 , one end of which is connected to the driving signal input port Vgate, and the other end of which is connected to a connection point between one end of the resistor R1 and one end of the capacitor C1 .

8. The gallium nitride driving circuit according to any one of claims 1 to 6, characterized in that: The gallium nitride driving circuit further includes a diode D4 , wherein a cathode of the diode D4 is connected to the driving signal input port Vgate, and an anode of the diode D4 is connected to a connection point between one end of the resistor R1 and one end of the capacitor C1 .

9. The gallium nitride driving circuit according to any one of claims 1 to 6, characterized in that: The gallium nitride driving circuit also includes a resistor R2 and a diode D4; one end of the resistor R2 is connected to the driving signal input port Vgate, and the other end of the resistor R2 is connected to the connection point between one end of the resistor R1 and one end of the capacitor C1; the cathode of the diode D4 is connected to the driving signal input port Vgate, and the anode of the diode D4 is connected to the connection point between one end of the resistor R1 and one end of the capacitor C1.

10. A switching power supply comprising a gallium nitride power tube, characterized in that: The switching power supply further comprises the gallium nitride driving circuit according to any one of claims 1 to 9, and the driving signal output port Vgs is connected to the gate of the gallium nitride power tube.

Images